1. Field of the Invention
This invention relates to high impact resistant polymeric materials and processes for making them.
2. Description of the Prior Art
Polymer blends of polymethyl methacrylate and ethylene-vinyl acetate for impact resistance have been suggested by others; for example Deichert et al, U.S. Pat. No. 3,646,164, Kiuchi et al, U.S. Pat. No. 3,742,090, Schmitt et al, U.S. Pat. No. 3,700,754, and Ennor et al Canadian Patent 697,734. However, none of the materials produced under the prior art have become commercially successful due to certain deficiencies in properties of the resultant materials, including relatively low modulus, poor clarity, and low service temperature. Electron microscopy of the prior art materials indicate a polymer morphology resembling either typical filled rubber, i.e., small discrete particles of glassy polymer in a largely continuous rubber matrix, or a continuous glassy matrix containing discrete rubber particles.